Map of Palliser's Triangle. Canadian section of the Coteau du Missouri

The Coteau du Missouri, or Missouri Plateau, is a large
plateau that stretches along the eastern side of the valley of the
Missouri River in central
North Dakota and north-central
South Dakota in the United States.[1][2] In the Canadian provinces of Saskatchewan and Alberta this physiographic region is classified as the uplands Missouri Coteau, which is a part of the Great Plains Province or Alberta Plateau Region, which extends across the south west corner of the province of
Saskatchewan as well as the south east corner of the province of
Alberta.[3] Historically, in Canada the area was known as the
Palliser's Triangle regarded as an extension of the Great American Desert and unsuitable for agriculture and thus designated by Canadian
geographer and
explorerJohn Palliser. The terrain of the Missouri Coteau features low hummocky, undulating, rolling hills, potholes, and grasslands.[4]

The plateau is poorly drained and is interspersed with glacial
kettle lakes. It is transversed by several broad
sags marking the ancient stream valleys of the eastern continuations of the
Grand,
Moreau,
Cheyenne,
Bad, and
White rivers.